Merge pull request #8584 from boesing/feature/8521

Enhance type detection for internal php functions `key`, `current`, `end` and `reset`
vimeo · Oct 17, 2022 · 48b8efd · 48b8efd
2 parents 4025ce7 + eb6bbfb
commit 48b8efd
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Showing 4 changed files with 137 additions and 5 deletions.
diff --git a/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayPointerAdjustmentReturnTypeProvider.php b/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayPointerAdjustmentReturnTypeProvider.php
@@ -19,9 +19,19 @@
 
 use function array_merge;
 use function array_shift;
+use function in_array;
 
 class ArrayPointerAdjustmentReturnTypeProvider implements FunctionReturnTypeProviderInterface
 {
+    /**
+     * These functions are already handled by the CoreGenericFunctions stub
+     */
+    const IGNORE_FUNCTION_IDS_FOR_FALSE_RETURN_TYPE = [
+        'reset',
+        'end',
+        'current',
+    ];
+
     /**
      * @return array<lowercase-string>
      */
@@ -82,7 +92,7 @@ public static function getFunctionReturnType(FunctionReturnTypeProviderEvent $ev
 
         if ($value_type->isEmpty()) {
             $value_type = Type::getFalse();
-        } elseif (($function_id !== 'reset' && $function_id !== 'end') || !$definitely_has_items) {
+        } elseif (!$definitely_has_items || self::isFunctionAlreadyHandledByStub($function_id)) {
             $value_type->addType(new TFalse);
 
             $codebase = $statements_source->getCodebase();
@@ -102,4 +112,9 @@ public static function getFunctionReturnType(FunctionReturnTypeProviderEvent $ev
 
         return $value_type;
     }
+
+    private static function isFunctionAlreadyHandledByStub(string $function_id): bool
+    {
+        return !in_array($function_id, self::IGNORE_FUNCTION_IDS_FOR_FALSE_RETURN_TYPE, true);
+    }
 }
diff --git a/stubs/CoreGenericFunctions.phpstub b/stubs/CoreGenericFunctions.phpstub
@@ -136,14 +136,54 @@ function array_flip(array $array)
  *
  * @param TArray $array
  *
- * @return (TArray is array<empty, empty> ? null : TKey|null)
+ * @return (TArray is array<empty,empty> ? null : (TArray is non-empty-list ? int<0,max> : (TArray is non-empty-array ? TKey : TKey|null)))
  * @psalm-pure
  * @psalm-ignore-nullable-return
  */
 function key($array)
 {
 }
 
+/**
+ * @psalm-template TKey as array-key
+ * @psalm-template TValue
+ * @psalm-template TArray as array<TKey, TValue>
+ *
+ * @param TArray $array
+ *
+ * @return (TArray is array<empty,empty> ? false : (TArray is non-empty-array ? TValue : TValue|false))
+ * @psalm-pure
+ */
+function current($array)
+{
+}
+
+/**
+ * @psalm-template TKey as array-key
+ * @psalm-template TValue
+ * @psalm-template TArray as array<TKey, TValue>
+ *
+ * @param TArray $array
+ *
+ * @return (TArray is array<empty,empty> ? false : (TArray is non-empty-array ? TValue : TValue|false))
+ */
+function reset(&$array)
+{
+}
+
+/**
+ * @psalm-template TKey as array-key
+ * @psalm-template TValue
+ * @psalm-template TArray as array<TKey, TValue>
+ *
+ * @param TArray $array
+ *
+ * @return (TArray is array<empty,empty> ? false : (TArray is non-empty-array ? TValue : TValue|false))
+ */
+function end(&$array)
+{
+}
+
 /**
  * @psalm-template TKey as array-key
  * @psalm-template TArray as array<TKey, mixed>

diff --git a/tests/ArrayFunctionCallTest.php b/tests/ArrayFunctionCallTest.php
@@ -1085,7 +1085,7 @@ class Foo {
                     $a = ["one" => 1, "two" => 3];
                     $b = key($a);',
                 'assertions' => [
-                    '$b' => 'null|string',
+                    '$b' => 'string',
                 ],
             ],
             'keyEmptyArray' => [
@@ -1100,12 +1100,90 @@ class Foo {
                 '<?php
                     /**
                      * @param non-empty-array $arr
-                     * @return null|array-key
+                     * @return array-key
                      */
                     function foo(array $arr) {
                         return key($arr);
                     }',
             ],
+            'current' => [
+                '<?php
+                    $a = ["one" => 1, "two" => 3];
+                    $b = current($a);',
+                'assertions' => [
+                    '$b' => 'int',
+                ],
+            ],
+            'currentEmptyArray' => [
+                '<?php
+                    $a = [];
+                    $b = current($a);',
+                'assertions' => [
+                    '$b' => 'false',
+                ],
+            ],
+            'currentNonEmptyArray' => [
+                '<?php
+                    /**
+                     * @param non-empty-array<int> $arr
+                     * @return int
+                     */
+                    function foo(array $arr) {
+                        return current($arr);
+                    }',
+            ],
+            'reset' => [
+                '<?php
+                    $a = ["one" => 1, "two" => 3];
+                    $b = reset($a);',
+                'assertions' => [
+                    '$b' => 'int',
+                ],
+            ],
+            'resetEmptyArray' => [
+                '<?php
+                    $a = [];
+                    $b = reset($a);',
+                'assertions' => [
+                    '$b' => 'false',
+                ],
+            ],
+            'resetNonEmptyArray' => [
+                '<?php
+                    /**
+                     * @param non-empty-array<int> $arr
+                     * @return int
+                     */
+                    function foo(array $arr) {
+                        return reset($arr);
+                    }',
+            ],
+            'end' => [
+                '<?php
+                    $a = ["one" => 1, "two" => 3];
+                    $b = end($a);',
+                'assertions' => [
+                    '$b' => 'int',
+                ],
+            ],
+            'endEmptyArray' => [
+                '<?php
+                    $a = [];
+                    $b = end($a);',
+                'assertions' => [
+                    '$b' => 'false',
+                ],
+            ],
+            'endNonEmptyArray' => [
+                '<?php
+                    /**
+                     * @param non-empty-array<int> $arr
+                     * @return int
+                     */
+                    function foo(array $arr) {
+                        return end($arr);
+                    }',
+            ],
             'arrayKeyFirst' => [
                 '<?php
                     /** @return array<string, int> */

diff --git a/tests/TypeReconciliation/EmptyTest.php b/tests/TypeReconciliation/EmptyTest.php
@@ -259,7 +259,6 @@ function contains(array $data, array $needle): bool {
 
                         while (!empty($needle)) {
                             $key = key($needle);
-                            if ($key === null) continue;
                             $val = $needle[$key];
                             unset($needle[$key]);